The inventive concept relates to photomasks, and more particularly, to photomasks and methods of fabricating the photomasks, which may improve the dispersion of critical dimensions (CDs) of patterns in the photomask.
Photomasks are a high-precision plate used to form an integrated circuit (IC) on a wafer. Photomasks may include a transparent substrate and a light-blocking pattern formed on one surface thereof. The light-blocking pattern of the photomask defines a circuit pattern on the wafer through an exposure process. Theoretically, a CD of the light-blocking pattern of the photomask has to precisely correspond to a CD of a circuit pattern formed on the wafer using the light-blocking pattern. Here, the CD of the light-blocking pattern of the photomask may correspond to the CD of the corresponding circuit pattern formed on the wafer with the same magnification or different magnifications. However, the CD of the light-blocking pattern of the photomask may differ from the CD of the circuit pattern formed on the wafer because of defects of an exposure system, such as a spatial distribution failure of a light source or lens defects, and errors in the light-blocking pattern of the photomask. In recent years, with the subminiaturization of patterns, more attention has been paid to improving the dispersion of CDs on a wafer in a hot-spot area that has an insufficient patterning margin.